Phys.org August 13, 2021 A promising and potentially scalable hardware platforms and computational protocols is to combine a photonic platform with measurement-induced quantum information processing. Gate operations can be implemented through optical measurements on a cluster state. Researchers in Denmark designed and demonstrated the deterministic implementation of a multi-mode set of measurement-induced quantum gates in a large two-dimensional optical cluster state using phase-controlled continuous-variable quadrature measurements. Each gate is programmed into the phases of high-efficiency quadrature measurements, which execute the transformations by teleportation through the cluster state. They executed a small quantum circuit consisting of 10 single-mode gates and 2 […]
Effectively removing carbon dioxide from the atmosphere
Phys.org August 13, 2021 Direct air carbon capture and storage (DACCS) is a comparatively new technology for removing carbon dioxide from the atmosphere. Since it would allow large amounts of CO2 to be trapped this technology could also reduce the greenhouse effect. To investigate how effectively this could be implemented with different system configurations of a certain process, researchers in Switzerland analyzed a total of five different configurations for capturing CO2 from the air and their use at eight different locations around the world. Autonomous system layouts prove to be a promising alternative, with a green house gases removal efficiency […]
Engineers make critical advance in quantum computer design
Phys.org August 13, 2021 Advancing from the current few-qubit devices to silicon quantum processors with upward of a million qubits, as required for fault-tolerant operation, presents several unique challenges, one of the most demanding being the ability to deliver microwave signals for large-scale qubit control. Researchers in Australia have demonstrated a potential solution to this problem by using a three-dimensional dielectric resonator to broadcast a global microwave signal across a quantum nanoelectronic circuit. The technique uses only a single microwave source and can deliver control signals to millions of qubits simultaneously. They have shown that the global field can be […]
Ice formation on surfaces enhanced via a non-classical nucleation process
Phys.org August 17, 2021 Understanding the process of ice formation can decelerate the rate at which glaciers melt and sea levels rise and alleviate other major environmental concerns. To better understand the non-classical nucleation theories researchers at the University of Hong Kong combined Markov State Models (MSMs) and transition path theory (TPT) to identify intermediate states of disordered ice mixtures and compare parallel pathways (classical vs. non-classical). This advantage helped unravel the underlying mechanisms of non-classical nucleation processes and the co-existence of the two pathways. They showed that the disordered mixing of ice stabilizes the critical nucleus and makes the […]
Metasurfaces control polarized light at will
Phys.org August 14, 2021 A team of researchers in the US (Harvard University, industry) has proposed a new class of computer-generated holograms, called Jones matrix holograms, whose far-fields have designer-specified polarization response. They have provided a simple procedure for their implementation using form-birefringent metasurfaces. Jones matrix holography generalizes past work with a consistent mathematical framework, particularly in the field of metasurfaces. They have demonstrated holograms whose far-fields implement parallel polarization analysis and custom waveplate-like behavior. The new approach could lead to applications in diverse fields including imaging, microscopes, displays, and astronomy. The work shows that the ability to switch between […]
Nanostructure-based lasers for information and communication technologies
Phys.org August 18, 2021 Key applications in 5G and 6G optical networks require the utilization of laser sources to perform complex tasks at ultra-fast speed and to enable broadband, secure and energy efficient communications. An international team of researchers (France, USA – University of New Mexico) reviews recent findings and prospects on nanostructure based light emitters where active region is made with quantum-dot and quantum-dash nanostructures. To link the material and fundamental properties with the device physics, they closely examined spectral linewidth, polarization anisotropy, optical nonlinearities as well as microwave, dynamic and nonlinear properties. The paper focuses on photonic devices […]
New salts raise the bar for lithium ion battery technology
Phys.org August 16, 2021 Lithium battery materials, currently in use, fall short in terms of safety and performance holding back the next generation of high-performance batteries. In particular, the development of the electrolyte poses a key challenge for higher power batteries suitable for energy storage and vehicle applications. Researchers in Australia have synthesized safe fluoroborate salts with battery grade purity by recrystallisation process. When put in a lithium battery with lithium manganese oxide cathodes, the cell cycled for more than 1000 cycles, even after atmospheric exposure. The salt was found to be very stable on aluminum current collectors at higher […]
On the road to faster and more efficient data storage
Phys.org August 18, 2021 Antiferromagnet is a promising candidate for developing the next generation of information technology. An international team of researchers (Germany, Sweden, Japan, Italy) showed that domain walls play an active role in the dynamic properties of the antiferromagnet nickel oxide. The experiments revealed that magnetic waves with different frequencies could be induced, amplified, and even coupled with each other across different domains—but only in the presence of domain walls. The ability highlights the potential to actively control the propagation of magnetic waves in time and space as well as energy transfer among individual waves at the femtosecond […]
A peculiar state of matter in layers of semiconductors
MIT News August 19, 2021 Experimental realization of many-body localization (MBL) in solid-state systems has remained challenging. A team of researchers in the US (MIT, Argonne National Laboratory, Brookhaven National Laboratory, University of Wisconsin, Oak Ridge National Laboratory, UC Santa Barbara, University of Pennsylvania) reports evidence of a possible phonon MBL phase in disordered GaAs/AlAs superlattices. Through grazing-incidence inelastic X-ray scattering, they observed a strong deviation of the phonon population from equilibrium in samples doped with ErAs nanodots at low temperature, signaling a departure from thermalization. This behavior occurs within finite phonon energy and wavevector windows, suggesting a localization-thermalization crossover. […]
Scientists Discover How to Make Glass So Hard, It Can Even Scratch Diamond
Science Alert August 13, 2021 An international team of researchers (China, Sweden, USA – Harvard university, Germany, Russia) has discovered the critical proportion of crystallized and amorphous carbon needed to create a glass with remarkable properties that won’t weaken under intense pressure. By subjecting spheres of carbon atoms to intense pressure and baking at temperatures between 1,000 and 1,200 degrees Celsius they obtained glassy materials dubbed AM – I, II and III. After tests they mapped the way the atoms bonded with one another, showing they all operated as a semiconductor on a level comparable with amorphous silicon. After Vickers […]